Ooooo, this is so much fun, I get such a greater range of randomized hue’s this way:
byte BEAT_3 = beatsin8( 6, 0, 255);
byte BEAT_4 = beatsin8( 2, 0, 255);
average = (BEAT_3 + BEAT_4) / 2;And do start getting more of the possible range of colors, I vary the saturation and brightness of the CHSV assignment:

1) I connected a pot to vary the bpm of a fade in / out effect. The pot helps me beat-match to any music manually. However as with standard dj’ing cases I also need a button to reset the timer. Think of it as the play button of cd-dj’s. It will re-start my sine beat at the exact top. The bpm wont change though.

I read your #define USE_GET_MILLISECOND_TIMER 1 however still not clear. Cannot get my head to wrap around the details and uses of the timing. Do you have any sources I can read on this? or do you have a code example?